Improvement in key-fasteners



J. T. WHITE. Key -Pasteners.

No. 201,373. Pat ented March l9, I878.

an J37 IVjtneaws:

UNITED STATES PATENT OFFICE.

JOHN T. WHITE, OF ARLINGTON, ASSIGNOR OF ONE-HALF HIS RIGHT TO RUFUS S. MERRILL, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN KEY-FASTENERS.

Specification forming part of Letters Patent No. 201,373, dated March 19,1878; application filed February 28, 1878.

To all whom it may concern:

Be it known that I, J OHN'YT. WHITE, of Arlington, in the coimty of Middlesex and State of Massachusetts, have invented a new and useful Improvement in Key-Fasteners, of which the following is a specification:

My invention relates to a key-fastening device arranged in connection or in combination with the usual key-hole guard, by which it will be impossible for a person who is on the side of the door opposite that in which the key is inserted to turn the key in the look by the aid of nippers or any other implement.

My invention consists in combining with a key-hole guard-plate vertical guides on each side of the hole, and a cam-shaped lever pivoted to the lower end, by which construction the slotted sliding clamp, when in its position below the key, will be prevented, owing to its gravity, from accidentally engaging with the key; and further consists in providing the sliding clamp with a slot on one end, of such size as will embrace the notches on the stem of key, and with a slot on the other end, of such size as will allow the stem of the key to turn, but will prevent the key from accident ally falling out.

Figure l in the drawing is an elevation of a mortise-lock with key-hole guard embodying my improvement, showing the key fastened. Fig. 2 is a view of the key-hole guard, showing the guides and cam of my fastener. Fig. 3 is a view of the sliding clamp which secures the key. Fig. 4 is a view of a sliding clamp with both ends slotted.

A is the plate constituting the usual keyhole guard. 12 are vertical guides, one on each side of the key-hole. c is the sliding clamp, which moves in the guides, and has in the upper end a slot, d, with parallel sides, and of size just large enough to let the key enter the key-hole. fis a cam-shaped lever, pivoted on the lower part of the plate and below the sliding clamp. The stem or shank of the key is provided with flattened sides or notches, so that when the key is turned in the lock to shoot the bolt, the said notches will be found in position to allow the clamp to slide up andem"- brace them, which movement it will be caused tomake by turning the cam. While the notch es on the stem of the key are thus embraced or clamped, the keyhole is also covered, and all attempts to pick the lock or turn or push out the key would be futile. Y

The other end of the clamp 0 may also be provided with a slot, e, as shown in Fig. 4, large enough to allow the stem of the key to wholly turn. By removing the key the sliding clamp may be reversed, and the key again inserted and the cam turned up. Thus arranged, the key may be turned at pleasure, but cannot fall out.

I claim- 1. The key-fastener consisting of a vertical guide attached to the plate oneach side of the key-hole, and the upward-slidin g clamp 0, provided on its upper end with a slot, as described, and the cam-shaped lever f, pivoted on the lower part of the plate, as shown and described.

2. In a detachable sliding clamping-plate of a key-fastener, providing one end with a slot, d, to embrace the notches on key-stem to fasten the key, and providing the other end with a slot, 0, to allow key to turn, but prevent it from falling out, as set forth.

JOHN T. WHITE. 

